Reaction furnace and evaporator



June 2,` 1953 w. s. BOWEN ETAL REACTION FURNACE AND EVAPORATOR Filed Oct. 8. 1949 IN V EN TORS Patented June 2, 1953 REACTIONFRNACE AND EVAPORATAO'R William v'Spencer Bowen, Westfield, N.J.,and Jhn Vi'Scalll, New Yrk, lN. Y.

Application October, 1949, Serial No. 120,370

This inven-tion relates v'to furnaces and more particularly to vfurnaces'for.1 J'e'rforrnin'gsuch operations as Aevaporating aqueous waste products, reducing ores and reacting certain materials under the inuen'ce of heat.

iThe efficiency of high speed evaporation and reaction furnaces, used in the "treatment of various materials is, as a general rule, dependent upon the intimacy. uniformity and speed with whichthe materials being treated canbe exposed tothe action of thermal gas or other vtreating media Within the evaporating or reacting vcham'- ber. Thus, vif a relatively large amount 'of heat can be imparted to a given material within a relatively short time interval, the size of the .furnace maybe materially decreased in propor- 'tionto its output.

Accordingly, it is an object of this invention to provide a furnace for performing various reducing and evapor'ating operations in relatively short time intervals in 'relation to the size of the "furnace,

It is another object'of the inventionto'provide a'furnace for use in tthetreatment of wasteproductjs such as sewage sludge whereby the evapora- 'tion of large quantities of AWater and the incinera- "tio'n'of solids contained `therein `-may be accomplishedin such a wayas to preclude vthe forma- "tion of odorous gases "and to prevent ash deposits irom reaching the atmosphere.

vIt is a `further object ofthe invention to pro- 'vi'de'a reaction furnace 'useful in a continuous Vsystem for 'preparing metal from ore.

VAccording to the invention,'a vfurnace is procylindrical combustion `chamber. This is aecomplished by injecting "fueltan'gentially in the upper reaches of the chamber "to r'establish a descending flamevortextherein and tangentialofthe `fuel injection, finely divided materials to be `evapor'atedor treated Within the 'chamber to provide "asecond descending vortex moving in and intimately commingling therewith to .form a single descending vortex, wherein lany `relativ-ely densefparticles-aresegregated toward the wall by tangential farce `for; removal. through. a

lateral skimming slot at the bottom.

2 Claims. (Cl. 15S-"4) `the-'same angular vdirection as the `amevortex Additional objects and ladvantages of the invention will become apparent from the 7following 'detailed description of a furnace'formed according to 'the invention and taken in conjunction with the accompanying drawings, in which:

Fig. l is -a 4'top -view vof a'iurnace with its external structural supports removed;

Fig. 2 is a cross sectional 'side view'o the furnace taken along line -2-2of Fig. l; and

FigfS'is a view inside elevation of the-furnace.

The illustrated furnace kas formed according to the invention includes'an upright cylindrical reaction or vevaporation chamber I0 `having at its upper -end a pair of vertically and circumferen- 'tially spacedtangential inlet ports Hand I2. A cylindrical -flue portion I3, in axial .alignment with the `cylindrical ehamb'er I0, is .provided at `the upper :end of the `chamber and .extends :downwardly to a pointfadjacent the lower, .tangential inlet port II.

Thevlow'er--en'd of the -reactioncharnber is provided with 4a preferably Aarched or Aconvex floor portion I4 'having Yan aperture I5f0n 'theaxis or center? line 'of theichamben A peripheral skim- ;ming slot I6 opening against the movement of the commingled yvortices `is lformed in the wall of 'the chamber at its lower yend, and is adapted to discharge into a receptacle or vhopper Il disposed vbeneath the reaction chamber. The lreceptacle I'I hasas its roof portion the .apertured floor portion I4 of the r.reaction chamber, -t-hus .providing for communication between .the .receptacle and the axial'centerbf the combustion chamber.

4Fuel such-as .gas or oil, for example, from a Aconduit I8, is forcibly injected tangentially through the vupper inlet lport I-2:into the chamber. Air 0roxygen enriched air from a conduit I9 may alsobe-introducedinto thechanrber concurrently with thefuell through the inlet port I2. The high-velocity, tangential injection through the vport I2 sets .up -a descending flame Vortex `Withinthe, chamber.

When-the furnace is used as adehydrating unit .for various `Waste materials, such as watered sludge for example, the material is forcibly-in- ,jected vfrom conduit 20 vtangentially into the ehambe-r throughv vthelowerport f I I in the form offa spraytherebyA toprovide-a descending vvortex moving inr thesameansular-,direction as and-comminglin'g with the flame vortex. The material entering through the port II is preferably finely divided so that relatively large surface areas are presented to the flames to increase the rate of evaporation or reaction.

Because the fuel inlet port I2 is disposed above the material inlet port II a flame roof is established in the upper end of the chamber which tends to prevent premature chilling of the flame.

The cylindrical flue portion I3, extending downwardly into the chamber I0, assists in the formation and shaping of the respective vortices which eventually become intimately commingled during the helical descent to the lower end of the chamber due to relatively high centrifugal forces which drive the particles and gases toward the walls of the chamber.

The united or commingled vortices engage the skimming slot I6 and residual solids such as ash, i

together with a portion of the gases are channelled into the lower receptacle I'I. As described, the receptacle I1 is vented through the aperture I5 to the center line of the chamber I0 which is coextensive with the core of the vortices formed within the chamber. The vortices thus produce a low static head along the axis of the chamber, whereas a high static head is formed at the peripheral skimming slot. A ow is thus set up within the lower receptacle from the point of discharge of the skimming slot inwardly to the aperture I5. The gases, in which a quantity of dust-like particles may be entrained, rise upward through the aperture I5 along the axis of the chamber wherein the particles are eventually drawn into the vortices and again subjected to the action of the thermal uid. By making the vertical height of the chamber of suflicient length with respect tothe diameter, particles will be caught in the vortex before leaving the chamber through the flue portion I3 disposed at its upper end, it having been found that a ratio of chamber length to internal diameter of between 2 and 4 gives. serviceable results. Accumulated solids in the receptacle Il may be drawn oif by an aspirator 30 through a conduit 3 I.

In order to encourage high vortex velocities within the reaction chamber, the walls thereof are preferably smooth to present minimum impedance to the ow. Accordingly, a metal walled chamber is preferable, and to protect the metal walls from overheating and help to maintain given temperature conditions of the gases formed within the chamber and discharging through the flue, a water jacket may be provided comprising an outer shell 2l encasing the inner shell I0. A plurality of through-bolts 22 are provided to maintain proper rigidity and spacing of the shells. The entire unit may then lbe encased by suitable lagging or insulation 23.

An inlet conduit 24 is provided for filling the water jacket, and water gauge connections 25 may be provided as the upper end thereof. A safety valve connection 2S may be provided, if required, to insure against the development of unsafe pressures within the jacket. The flue portion I3 is likewise provided with a water jacket formed by the inner shell or wall I3 and an cuter shell 2l. Apertures 28 are provided in the upper end of the shell 27 to permit a free passage of water from the water jacket surrounding the chamber I.

An outlet pipe 29 is provided at the upper end of the chamber for taking off steam or heated water generated within the water jacket. This steam or heatedwater, representing waste heat,

'4 may be utilized in certain instances in preheating or treating material injected into the furnace.

In utilizing the furnace as an evaporator for treating sewage sludge, for example, the eiiluent exhaust gases may be kept odorless by maintaining the chamber temperature in the range of 1500 F., this temperature being controlled by the fuel oil input and feed input, and Iby the amount of heat extracted by the aforedescribed water jacket system.

If the furnace is utilized for reducing ores such as iron ore, the ore is first finely divided and then injected tangentially into the furnace .through inlet II with carbonaceous powdered or liquid fuel such as powdered peat or fuel oil. Initial heat is applied to the furnace by means of a suitable fuel burner through the tangential inlet I2. Molten iron is then accumulated at the bottom of the chamber, from which point it may be drawn off continuously into the slag separating receptacle (not shown). Oxygen in the ore is removed and discharged through the flue I3 as CO2. Molten iron free of slag is then passed alternately into two electrical or open hearth furnaces for further purification of the metal, one emptying and filling while the other operates. Thus, the making of steel may be a continuous operation from the ore to the finished product.

From the foregoing it will be apparent that the invention provides a new and improved furnace utilizing a novel arrangement of components to provide for highly effective intermixing of fluidized solids and thermal fiuids Within the combustion chamber and for efcient separation of treated solids from the gases after the reaction period.

It will be understood that the several embodiments described by way of illustration may be modified within the spirit of the invention and the embodiments described, therefore, are not to be regarded as limiting in any way the scope of the following claims.

We claim:

l. In a cyclone furnace, in combination, a vertical axis combustion chamber having a substantially circular cross section, fuel injection means for establishing a descending iiame vortex within the chamber, material injection means for establishing a descending vortex of material to be treated, said flame and material vortices moving in the same angular direction, an axially disposed flue at the upper end of the chamber, a peripherally disposed skimming slot at the lower end of the chamber, a receptacle disposed beneath said combustion chamber adapted to receive the discharge from said skimming slot, a roof-portion for said receptacle having an opening communicating with the lower end of the combustion chamber on the axis thereof to permit a flow of material from said receptacle upwardly into the low static head created along the axis of said chamber by said vortices.

2. A furnace including a vertically disposed combustion chamber having a substantially circular cross section, first means including fuelsupplying means and inlet means for injecting fuel tangentially into the chamber in the upper portion thereof to form a descending flame vortex therein, second means including material-supplying means and inlet means disposed below said first means for tangentially injecting material to be treated into the chamber to form a descending vortex moving in the same annular direction as the flame vortex, said descending vortices being commingled within the chamber, the upper por- References Cited in 'bhe file 0f this patent UNITED STATES PATENTS Number Name Date Stilwell Mar. 13, 1883 De Laval July 30, 1907 Bowen July 23, 1929 Rogers Apr. 7, 1931 Hodson et a1 Dec. 26, 1939 Hodson et al. June 23, 1942 Hodson et al Dec. 19, 1944 Keith July 20, 1948 Komline May 5, 1950 Ramsing Nov. 14, 1950 

